DEEP SEATED PROGNOSIS OF THE GOLD DEPOSITS IN THE JIAPIGOU REGION

The Jiapigou gold mine,located in Jilin Province,is one of the earliest mined and the most important gold-producing area in China. But now its minable reserves are decreasing and becoming insufficient. This paper provides a prospective prognosis by comprehensive studies of the vertical variations of primary geochemical halo data in orebodies and near wall rocks,ore mineral association and thermoelectricity of pyrites. The primary geochemical halo data are generally characterized by Au,Ag,Pb,Mo and Ti anomalies in the upper part of orebodies,Bi,Zn,Mn,W and Mo anomalies in the middle,As,Sb,Hg,Cu,Pb and Ag anomalies in the lower. The ore mineral associations feature a large amount of base metal sulfides occurring in the top and the lower part of orebodies. The thermoelectrictity of pyrites is of negative value and trends larger with the increase of depth. All of these characteristics are different from the vertical normal zonation in hydrothermal gold deposits such as Jiaodong and other regions. These prospective prognoses imply that there are still undiscovered deep-seated orebodies under the present mining level in the deposits of Erdaogou,Dazhujuan,Xiaxitai and Dongtuoyaozi.